-4.9x^2+49x+30=0

Solution for -4.9x^2+49x+30=0 equation:

-4.9x^2+49x+30=0

a = -4.9; b = 49; c = +30;
Δ = b2-4ac
Δ = 492-4·(-4.9)·30
Δ = 2989
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2989}=\sqrt{49*61}=\sqrt{49}*\sqrt{61}=7\sqrt{61}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(49)-7\sqrt{61}}{2*-4.9}=\frac{-49-7\sqrt{61}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(49)+7\sqrt{61}}{2*-4.9}=\frac{-49+7\sqrt{61}}{-9.8}
$